JP5616366B2 - Foam forming system with low vapor pressure - Google Patents

Description

  The present invention is a foam-forming system using 1,1,1,2-tetrafluoroethane (“HFC-134a”) and water as a blowing agent, characterized by a reduced vapor pressure, And a process for producing a foam from the system.

  Formulations and methods for producing foams, particularly rigid polyurethane foams, are known. Foam manufacturers have replaced CFC and HCFC blowing agents that destroy the ozone layer with environmentally favorable blowing agents. Among the blowing agents, hydrofluorocarbons (“HFCs”) are used. Many of these alternative blowing agents have sufficiently low boiling points so that they exist in gaseous form at standard ambient temperatures and pressures (20-30 ° C. and 15 absolute psi or less). Thus, unless the formulation containing the blowing agent is stored under conditions of low temperature and / or pressure to ensure the foaming agent is dissolved in the liquid state, the blowing agent is used in the foam-forming formulation immediately before use. Could not be blended. See the specifications of US Pat. Nos. 3,541,023, 5,451,614 and 5,470,891.

  The blowing agent is generally incorporated in the "B-side" of the foam-forming mixture in an amount of about 3 to about 25% by weight. In use, the gaseous blowing agent is typically added to the foamer's day tank prior to foaming. For this reason, foam manufacturers need to handle gaseous foaming agents, and the foaming agents must be accurately blended. The gaseous blowing agent may be added with the isocyanate and isocyanate-reactive component as a separate third stream at the mixing head.

  A gaseous blowing agent may be added to the “B-side” (ie, isocyanate-reactive component) prior to foaming during compounding of the isocyanate-reactive component. However, in this case, it is necessary to store the formulation formulated with the blowing agent under controlled temperature and pressure conditions, which increases the cost of handling and storing the formulation. Accordingly, it would be advantageous to develop a foam-forming formulation that can incorporate a blowing agent such as HFC134a that is gaseous at standard ambient conditions and that has a substantially lower vapor pressure.

  U.S. Pat. No. 4,972,003 teaches that the use of more than 140 equivalents of isocyanate-reactive compounds promotes the solubility of HCFCs and HFC blowing agents with boiling points less than 272 ° K. Yes. However, this patent document does not teach that the disclosed isocyanate-reactive compound and blowing agent mixture is sufficiently stable that it does not exhibit a significant vapor pressure. The disclosure does not suggest that foams can be made from the disclosed “stable” compositions by manual mixing techniques.

  US Pat. No. 5,578,651 describes a polyisocyanate comprising an isocyanate-reactive compound having a molecular weight of 92 to 10,000 and having at least two hydrogen atoms, an HFC blowing agent, and a solubilizing agent. And a process for the production of rigid polyurethane foam that is reacted in the presence of other optional additives. 1,1,1,4,4,4-hexafluorobutane (“HFC356”) is taught to be a preferred blowing agent, and the blowing agent is used in the examples described in the disclosure. Is the only blowing agent. Solubilizers that are considered useful are represented by a specific chemical formula. Preferred solubilizers include propylene carbonate, triethyl phosphate, tributyl phosphate and dioctyl phthalate. The patent document teaches that the use of one of the essential solubilizers increases the solubility of the partially fluorinated hydrocarbon, thus providing a single phase polyol component. However, this patent document does not teach that the use of any of the solubilizers disclosed therein sufficiently stabilizes the isocyanate-reactive component such that it does not exhibit a significant vapor pressure. The patent document does not teach that foams can be produced by manual mixing techniques from the isocyanate-reactive mixtures disclosed therein.

  US Pat. No. 6,262,136 describes a storage stable foam in which an alkylphenol or phenol having at least one phenolic hydroxyl group is incorporated into an isocyanate-reactive composition comprising a polyol and an organic blowing agent. A forming system is disclosed. The blowing agent used must contain at least one hydrogen atom and at least one fluorine atom and must be gaseous at ambient pressure. Among the phenols or alkylphenols, ethoxylated phenols, especially ethoxylated nonylphenol, resorcinol, catechol, hydroquinone, 1,2,3-trihydroxybenzene, 1,3,5-trihydroxybenzene and 1,2,4-triphenol Hydroxybenzene is taught as suitable for use in the compositions disclosed in this patent document. The patent document teaches that the disclosed system is storage stable for up to 3 months, but does not teach that the system is sufficiently stable that it does not exhibit significant vapor pressure. . The patent document also does not teach that foams can be produced from the isocyanate-reactive compositions disclosed therein by manual mixing techniques.

  When a solubility-enhancing additive is formulated in the B-side in a specific combination, an unexpectedly high concentration of gaseous blowing agent 1,1,1,2-tetrafluoroethane (HFC-134a) and water are added under atmospheric pressure. It became clear that it can be mix | blended with the B side of a foam formation composition. The blended blowing agent does not separate from the other components present on the B side, and the blowing agent is significantly greater than the pressure exhibited by HFC-134a in the isocyanate-reactive component without the essential additives in the present invention. Shows a small pressure.

  An object of the present invention is to provide a storage stable, isocyanate-reactive composition containing a blowing agent composition comprising significant amounts of both HFC-134a and water.

  Another object of the present invention is to provide a storage stable polyol / blowing agent composition that can be transported and stored under ambient temperature and reduced pressure.

  The object of the present invention is also sufficiently stable to contain a significant amount of HFC-134a and water, such that the vapor pressure exhibited by HFC-134a is lower than in the case of a composition without the essential additives of the present invention, It is to provide a storage stable polyol / blowing agent composition.

  It is a further object of the present invention to provide a storage stable polyol / foaming agent composition that can be manually mixed to produce rigid polyurethane foam.

  Another object of the present invention is to provide a method for producing a rigid foam having good physical properties, particularly a rigid polyurethane foam, from an isocyanate-reactive composition containing a blowing agent composition containing HFC134a and a specific amount of water. It is.

  The above and other objects apparent to those skilled in the art include (1) isocyanate-reactive compounds such as polyether polyols or polyester polyols, (2) HFC-134a, (3) water, (4) nonylphenol ethoxy. Achieved by combining rate and (5) propylene carbonate.

  The isocyanate-reactive composition of the present invention has a lower vapor pressure than the corresponding formulation, i.e., the same isocyanate-reactive compound, HFC-134a, and water, but no nonylphenol ethoxylate and propylene carbonate. In addition, it can be stored for 3 months before reacting with isocyanate to produce a foam such as rigid polyurethane foam.

2 is a graph showing vapor pressure-temperature curves for the formulations produced in Examples 1 and 2. FIG.

  The present invention relates to an isocyanate-reactive composition containing a blowing agent composition in which HFC-134a and water are present in significant amounts, and the use of the isocyanate-reactive composition to produce a foam.

  The isocyanate-reactive compound has a hydroxyl functionality or amino functionality of about 1 to about 8, preferably about 2 to about 6.5, and a hydroxyl number or amine number of about 25 to about 1850 mg KOH / g, preferably Those known to those skilled in the art, which are about 250-600 mg KOH / g, can be used in the practice of the present invention.

  Suitable isocyanate-reactive compounds generally include organic compounds having two or more isocyanate-reactive hydrogen atoms. Specific examples of suitable isocyanate-reactive compounds include polyols and polyamines. Polyols are particularly preferred. Specific examples of suitable polyols include polyester polyols, polyether polyols, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polyacrylates, polyhydroxy polyester amides and polyhydroxy polythioethers. Polyester polyols, polyether polyols and polyhydroxy polycarbonates are preferred.

  Suitable polyester polyols include reaction products of polyhydric alcohols (preferably dihydric alcohols to which trihydric alcohols may be added) and polybasic (preferably dibasic) carboxylic acids. It is done. In addition to polycarboxylic acids, the corresponding carboxylic acid anhydrides or polycarboxylic acid lower alcohol esters or mixtures thereof may be used for the preparation of polyester polyols useful in the practice of the present invention. The polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and / or heterocyclic, which may be substituted (eg by halogen atoms) and / or unsubstituted. Good. Specific examples of suitable polycarboxylic acids are succinic acid; adipic acid; suberic acid; azelaic acid; sebacic acid; phthalic acid; isophthalic acid; trimellitic acid; phthalic anhydride; tetrahydrophthalic anhydride; Tetrachlorophthalic anhydride; endomethylenetetrahydrophthalic anhydride; glutaric anhydride; maleic acid; maleic anhydride; fumaric acid; dimers and trimers of fatty acids such as oleic acid And may be mixed with fatty acid monomers; dimethyl terephthalate and bis-glycol terephthalate. Suitable polyhydric alcohols include: ethylene glycol; 1,2- and 1,3-propylene glycol; 1,3- and 1,4-butylene glycol; 1,6-hexanediol; 1,8-octanediol; Neopentyl glycol; cyclohexanedimethanol; (1,4-bis (hydroxymethyl) cyclohexane); 2-methyl-1,3-propanediol; 2,2,4-trimethyl-1,3-pentanediol; triethylene glycol Tetraethylene glycol; polyethylene glycol; dipropylene glycol; polypropylene glycol; dibutylene glycol and polybutylene glycol, glycerin and trimethylolpropane. The polyester may have a carboxyl end group in part. Lactones, such as caprolactone, or polyesters of hydroxycarboxylic acids, such as ω-hydroxycaproic acid, may be used.

  Suitable polycarbonates containing hydroxyl groups include those obtained by reaction of diols with phosgene, diaryl carbonates (eg diphenyl carbonate) or cyclic carbonates (eg ethylene or propylene carbonate). Specific examples of suitable diols include 1,3-propanediol; 1,4-butanediol; 1,6-hexanediol; diethylene glycol; triethylene glycol; and tetraethylene glycol. In the practice of the present invention, polyester carbonates obtained by reacting polyesters or polylactones (for example, those described above) with phosgene, diaryl carbonates or cyclic carbonates may be used.

  Suitable polyether polyols for the practice of the present invention include one or more starting compounds having a plurality of reactive hydrogen atoms and alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, Those obtained by known methods by reaction with epichlorohydrin or mixtures of these alkylene oxides. Polyethers preferably do not contain more than about 10% by weight of ethylene oxide units. Most preferably, the polyethers are obtained without the addition of ethylene oxide. Suitable starting compounds containing a plurality of reactive hydrogen atoms that can produce the polyether polyols include polyhydric alcohols (as described above suitable for the preparation of polyester polyols); water; methanol 1,2,6-hexanetriol; 1,2,4-butanetriol; trimethylolethane; pentaerythritol; mannitol; sorbitol; methylglycoside; sucrose; phenol; isononylphenol; resorcinol; hydroquinone; 1,-or 1,1,2-tris- (hydroxylphenyl) -ethane.

  Polyethers modified with vinyl polymers are also suitable for preparing the compositions of the present invention. Such modified polyethers can be obtained, for example, by polymerizing styrene and acrylonitrile in the presence of a polyether (US Pat. Nos. 3,383,351; 3,304,273; 3,523,095; 3,110,695 and German Patent 1,152,536).

  Polythioethers useful in the practice of the present invention include condensation products obtained using thiodiglycol alone and / or in combination with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or aminoalcohols. Is mentioned. These condensation products may be polythio mixed ethers, polythioether esters or polythioether ester amides, depending on the co-condensation component.

  Amine-terminated polyethers useful in preparing the compositions of the present invention include primary amines and halides at the ends or US Pat. Nos. 3,666,726; 3,691,112; 066,824; and 5,693,864, which can be prepared by reaction with a polyether having a leaving group such as mesylates. The amines are commercially available under the trade name Jeffamine.

  The isocyanate-reactive composition of the present invention may optionally contain a low molecular weight isocyanate-reactive compound. Suitable low molecular weight isocyanate-reactive compounds useful in the practice of this invention generally have from 1 to 3, preferably 2 hydroxyl groups and have an average molecular weight of from about 60 to about 200, preferably from about 100 to about 150. is there. Useful low molecular weight isocyanate-reactive compounds include the polyhydric alcohols described above as suitable for the preparation of polyester polyols and polyether polyols. Dihydric alcohols are preferred. The weight ratio of low molecular weight compound to high molecular weight compound containing two or more hydroxyl groups is generally from about 0.001 to about 2, and preferably from about 0.01 to about 0.40.

  Along with the isocyanate-reactive compounds described above, monofunctional compounds of the type generally known in polyurethane chemistry and small amounts of trifunctional or higher compounds may be used to produce the compositions of the present invention. If a slight branch structure is desired, for example, trimethylol may be used.

  In many cases, the isocyanate-reactive composition of the present invention is also added with a catalyst used for promoting the foam-forming reaction. Specific examples of catalysts useful for promoting the urethane reaction include di-n-butyltin dichloride, di-n-butyltin diacetate, di-n-butyltin dilaurate, triethylenediamine, bismuth nitrate, 1,4- And diazo-bicyclo- [2,2,2] octane, dimethylethanolamine, dimethylcyclohexylamine and pentamethyldiethylenetriamine.

  The blowing agent contained in the isocyanate-reactive composition of the present invention is a combination of 1,1,1,2-tetrafluoroethane (HFC-134a) and water. The boiling point of 1,1,1,2-tetrafluoroethane (HFC-134a) is -26 ° C. In the combination of HFC-134a and water blowing agent, HFC-134a is in an amount of 50-90 wt%, preferably 75-90 wt%, most preferably 75-85 wt%, based on the total weight of the blowing agent. Exists. Water is generally about 1.0 to about 4.0% by weight, preferably about 1.0 to about 3.5% by weight, and most preferably about 1.5 to about 3%, based on the total weight of the isocyanate-reactive formulation. Present in an amount of 0.0% by weight.

  In addition to HFC-134a and water essential in the present invention, known low boiling blowing agents may be used. However, such additional blowing agents should not be used in amounts that adversely affect the vapor pressure of the isocyanate-reactive composition, and generally exceed 20% by weight relative to the total weight of the blowing agent composition. Should not be used in quantities.

  The ethoxylated nonylphenol used to promote the solubility of HFC-134a in isocyanate-reactive compounds in the present invention is ethoxylated to the extent that the aromatic ring is present with at least 9 ethylene oxide groups on the ring. Phenol. Suitable commercially available ethoxylated nonylphenols include Igepal CO-630 (Chem Service), Tergitol NP-9 (Union Carbide) and Sulfonic N-95 ( And those marketed under the trade name of Texaco). Ethoxylated nonylphenol is generally added to the isocyanate-reactive component in an amount of 5 to 20% by weight, preferably 5 to 15% by weight, and most preferably 7 to 15% by weight, based on the total weight of the isocyanate-reactive component. Contained.

  Another compound used in the present invention to promote the solubility of HFC-134a in the isocyanate-reactive component is propylene carbonate. Propylene carbonate is generally contained in the isocyanate-reactive component in an amount of 5 to 20% by weight, preferably 5 to 15% by weight, most preferably 6 to 12% by weight, based on the total weight of the isocyanate-reactive component. Is done.

  The total amount of solubility promoter (ie, weight of ethoxylated nonylphenol + weight of propylene carbonate) contained in the isocyanate-reactive composition of the present invention is generally based on the total weight of the isocyanate-reactive composition. About 5 to about 30% by weight, preferably about 10 to about 20% by weight.

  The ethoxylated nonylphenol and propylene carbonate are such that the weight ratio of ethoxylated nonylphenol to propylene carbonate is 20: 80-80: 20, preferably 25: 75-75: 25, most preferably 30: 70-70: 30. Used in quantitative ratio.

  The blowing agent composition (ie, HFC-134a, water and all other blowing agents) is generally about 2 in the isocyanate-reactive composition of the present invention, based on the total weight of the isocyanate-reactive composition. In an amount of from about 20% by weight, preferably from about 5 to about 15% by weight.

  Optional components other than the flame retardant that may be contained in the isocyanate-reactive composition of the present invention, such as a catalyst and a surfactant, are based on the total weight of the isocyanate-reactive composition in the isocyanate-reactive component. In general, it is generally contained in an amount of 7% by weight or less, preferably about 0.1 to about 5% by weight.

  Any known isocyanates may be used to produce a polyurethane foam from the isocyanate-reactive composition of the present invention. Specific examples of suitable isocyanates include toluene diisocyanate (“TDI”), diphenylmethane diisocyanate (“MDI”), and polyphenylpolymethylene polyisocyanate (“polymer MDI”) and isocyanate-terminated prepolymers of these isocyanates. Can be mentioned.

  The isocyanate and isocyanate-reactive component can be reacted by any known method under normal processing conditions to form a polyurethane foam. Examples of suitable methods include manual mixing methods using compressed air driven or motorized mixers and conventional on-site injection methods for dispensing liquid mixtures.

  Isocyanates and isocyanate-reactive compositions are generally in an amount such that the equivalent ratio of isocyanate to isocyanate-reactive groups is from about 0.9 to about 2.5, preferably from about 1.0 to about 1.5. React.

  The storage-stable isocyanate-reactive composition of the present invention is stable at ambient temperature for a period of up to 3 months, generally for at least 2 months.

  Although the present invention has been described above, the present invention will be described in detail by the following examples. All parts and percentages described in the following examples are parts by weight and percentages by weight unless otherwise specified.

In the examples, the following raw materials were used;
Polyol A: An aromatic amine having an OH value of 385-405 mg KOH / g and a functionality of about 4, and commercially available from Bayer MaterialScience Limited Liability Company under the trade name Multranol 8114 Polyether polyol as an agent.
Polyol B: Based on sucrose having a functionality of about 5.8 and an OH value of 370 to 390 mg KOH / g and commercially available from Bayer MaterialScience Limited Liability Company under the trade name Multranol 4030 Polyether polyol.
Polyol C: a glycerin having a functionality of about 3.0 and an OH value of about 240 mg KOH / g, commercially available from Bayer MaterialScience Limited Liability Company under the trade name Arcol LHT-240 Polyether polyol as an initiator.
Polyol D: Poly having a functional value of about 5.2, an OH value of about 470 mg KOH / g, and a sucrose base material commercially available from Bayer MaterialScience Limited Liability Company under the trade name Multranol 4034 Ether polyol.
Polyol E: sucrose having a functionality of about 6.2 and an OH value of about 330 to about 350 mg KOH / g and commercially available from Bayer MaterialScience Limited Liability Company under the trade name Multranol 9171 Polyether polyol.
Polyol F: A polyether polyol having an OH number of 350 and a functionality of 3, and an initiator, which is an amine marketed by Bayer MaterialScience Limited Liability Company under the trade name Multranol 9170.
Polyol G: a propoxylated triol based on glycerin, having an OH number of about 470 and commercially available from Bayer MaterialScience Limited Liability Company under the trade name Multranol 9158.

PC; propylene carbonate SOL A; ethoxylated nonylphenol commercially available from Texaco under the trade name Surfonic N-95.
PC8; dimethylcyclohexylamine, commercially available from Air Products under the trade name Polycat 8.
HFC134a; 1,1,1,2-tetrafluoroethane.
B8484: a silicon surfactant commercially available from Evonik Goldschmidt under the trade name Tegostab B-8484.
B8465: A polyether-modified polysiloxane surfactant commercially available from Evonik Goldschmidt under the trade name Tegostub B-8465.
PV: Polyurethane forming reaction catalyst commercially available from Rhein Chemie under the name Desmorapid PV.
DB: Catalyst for polyurethane formation reaction that is commercially available from Rain Chemie under the name Desmolapid DB.
PCF; Tris (p-chloroisopropyl) phosphate, a flame retardant marketed by the company Great Lakes Chemical under the trade name Fyrol PCF.
NCO; polymeric diphenylmethane diisocyanate having an NCO content of 31.5% by weight and commercially available from Bayer MaterialScience Limited Liability Company under the name Mondur MR.

Example
Examples 1-2
Polyol A, PC and SOL A were each blended in the amounts shown in Table 1, and 400 g of this blend was placed in a 600 ml Parr pressure vessel equipped with a stirrer and pressure gauge. The sealed solution was then weighed and then all the air was removed from the headspace by a purge process that was repeatedly pressurized to 50 gauge psi and degassed using HFC-134a. Thereafter, 49.4 g of HFC-134a was added to prepare a formulation containing 11% (excluding the amount of blowing agent present in the head space) of HFC-134a.

  The formulation containing HFC-134a was then cooled to below 10 ° C. and allowed to equilibrate with stirring. The formulation was then warmed slowly and the vapor pressure and temperature were recorded periodically.

  The vapor pressure-temperature curves for these formulations are shown in FIG. This graph clearly shows that the combination of propylene carbonate and ethoxylated nonylphenol reduces the vapor pressure of HFC-134a in the formulation.

Examples 3-8
HFC-134a was blown into a container holding a formulation containing the ingredients listed in Table 2 in the amounts listed in Table 2 at ambient temperature and a pressure of about 730 mmHg. The amount of HFC-134a absorbed is shown in Table 2. 100 parts of the HFC-134a containing formulation listed in Table 2 was manually mixed with a defined amount of NCO for 10 seconds before being poured into the box forming the polyurethane foam. Table 2 shows the foam properties obtained from the blends that could be mixed manually. In Comparative Example 3, the desired amount of HFC-134a could not be added.

Example 9
In this example, the formulation of Example 5 was foamed with a Heneck HK-100 high pressure foaming machine equipped with a Hennek MQ-12 mixing head. Both the polyol and isocyanate temperatures were controlled at 70 ° F. and the total liquid throughput was adjusted to 57.5 lb / min. The prefoamed mixture was injected into a vertical panel mold with dimensions of 5 cm thickness x 20 cm width x 200 cm height and allowed to react. The main properties of the foams obtained from these panels are shown in Table 3.

  Although the present invention has been described in detail for purposes of illustration, these detailed descriptions depart from the object and scope of the invention, except for that purpose only and that it is limited by the claims. It should be understood by those skilled in the art that variations of the detailed description are possible without.

Claims (9)

An isocyanate-reactive composition containing a blowing agent and storage stable at ambient temperature,
a) polyols,
b) a blowing agent comprising HFC134a and water, and c) a stabilizing composition comprising (1) ethoxylated nonylphenol and (2) propylene carbonate, said stabilizing composition being a blowing agent b to polyol a) The isocyanate-reactive composition is used in an amount sufficient to promote solubility), and the stabilizing composition c) is present in an amount of 5 to 30 parts by weight relative to the total weight of the isocyanate-reactive composition. object.   The composition according to claim 1, wherein the polyol a) is one polyether polyol or a mixture of a plurality of polyether polyols. Ethoxylated nonyl phenol The composition of claim 1 present in an amount of 5 to 2 0 parts by weight relative to the total weight of the isocyanate-reactive composition.   The composition of claim 1, wherein the blowing agent comprises 50-90 wt% HFC-134a, based on the total weight of the blowing agent. The composition according to claim 4 , wherein water is present in an amount of 1 to 4 % by weight relative to the total weight of the isocyanate-reactive composition. The composition according to claim 1, wherein water is present in an amount of 1 to 4 % by weight relative to the total weight of the isocyanate-reactive composition.   A process for producing a rigid foam comprising reacting the isocyanate-reactive composition according to claim 1 with a polyisocyanate. The process according to claim 7 , wherein the polyisocyanate is a polyphenyl polymethylene polyisocyanate. A process for producing a rigid foam comprising reacting the isocyanate-reactive composition according to claim 1 with a polyisocyanate.

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